′�?, with a frequency of 295 cm−1, is attributed into the stretching vibration of Ga–Se bonds. The 2-phonon absorption with the 295 cm−one phonon corresponds for the crystal IR absorption edge, as an alternative to the residual absorption peak. Density functional concept computations show the residual absorption in the BGSe https://milondpcn.luwebs.com/33459410/the-smart-trick-of-baga4se7-crystal-that-no-one-is-discussing